Telephone-exchange system



A. E. LUNDELL. TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED AUG- I6. I916.

Patented Apr. 20, 1920.

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3 SHEETS-SHEET 2- Patented Apr. 20, 1920.

A. E. LUNDELLL TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED AUG-16, 1916.

H Ea? Patented Apr. 20, 1920.

3 SHEETS-SHEET 3- NQM A. E. LUNDELL. TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED AUG- 16, 19'6- UNITED STATE T ATEN T OFFICE.

ALBEN E. LUNDELL, OF NEW YORK, N. Y., ASSIGNOR TO WESTERN ELECTRIC COMPANY,

INCORPORATED, OF NEXV YORK, N. L, A

CORPORATION OF NEW YORK.

TELEPHONE-EXCHANGE SYSTEM.

Application filed August 15, 1916.

To all whom it may concern Be it known that I, ALnnN E. LUNDELL, a citizen of the United States, residing at New York, in the county of Bronx and State of New York, have invented certain new and useful Improvements in Telephone- Xchange Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to telephone ex change systems and more particularly to systems employing machine switching.

The object of this invention is to provide an arrangement by which a subscriber may be informed of his mistake if, for any reason, he sets the brushes of a switch on the terminals of an unequipped group.

In a full automatic system, a mistake of this nature might be made by the calling subscriber either mistaking the number of the desired line, or else operating his dial inaccurately. This contingency would arise more logically, however, in a semi-automatic system in which the calling subscriber might have looked up the desired number correctly, but have mistaken the oflice name, since it might happen that the office erroneously called would not have the groups representing the higher digits equipped. If this should happen and a switch be placed on unequipped terminals, the subscriber would have no way of knowing the reason for his failure to obtain a connection, and might continue to call the same number unsuccessfully, thus giving him the impression that the service was faulty.

A. feature of the invention is the extending of all unequipped terminals to answer ing jacks at a manual operators position, whereupon the operator will inform the calling subscriber that a mistake has been made.

The invention as shown is embodied in a semi-automatic telephone system of the type disclosed in Patent No. 1,168,319 to A. E. Lundell, issued January 18, 1916, but it is obviously capable of other adaptations. Only so much of the circuits and apparatus has been shown in the drawings as is necessary for a clear understanding of the invention.

The invention will be best understood from the following detailed description, reference being had to the accompanying drawings.

In the drawings, Figure 1 shows diagrammatically the substation apparatus of a calling subscriber, the answering cord of an op- Specification of Letters Patent.

Serial No. 115,208.

erator and the circuits of a selector having a group of unequipped terminals; Fig. 2 (to be placed to the right of Fig. 1) shows the circuits of a connector switch and the substation apparatus of the called subscriber; Fig. 3 (to be placed above Fig. 2) shows the incoming end of a trunk to an operators 7 position, and the operators answering cord.

The operation of the system is as follows: The subscriber at substation A desiring a connection, removes his receiver from the hook, whereupon line signals are displayed to an answerin operator in the well-known manner. The operator inserts a plug into a jack, the plug and jack terminals being indicated at 1 and 2. The operator is then informed of the number of the desired line, whereupon she operates a key set (not shown) controlling a sender diagrammatically indicated at 3, to set a first selector whose brushes and terminals are indicated at -11, 5 and 6.

It is now to be assumed that the first selector sequence switch is in position 11 and the sender sequence switch is in position 6. At this time, a relay 102 at the second selector is energized over a circuit from negative pole of battery, relay 102, second selector sequence switch contacts 103, 101, conductor 105, upper trunk conductor, first selector sequence switch contact 4:7, conductor 18, stepping relay 19, armature and back contact of the upper zero counting relay, sender sequence switch contact 50, conductor 51, first selector sequence switch contact 52, the lower trunk conductor and second selector sequence switch contact 106, to positive pole of battery. Relay 102 attracts its armatures and locks itself up at its lefthand armature over a circuit from negative pole of battery, relay 102, second selector sequence switch contacts 107 108, left-hand armature and front contact of relay 102, second selector sequence switch contacts 109, 10%, to the positive pole of the battery over the path previously described. Relay 102, at its right-hand armature, closes a circuit from positive pole of battery, its righthand armature and front contact, second selector sequence switch contacts 111, 112, and the winding of a power magnet 100 of the second selector sequence switch, to negative pole ofbattery. The second selector sequence switch moves out of position 1 and into position 2 under the control of its normal contact 101.

Patented Apr. 20, 1920.

In position 2 of the sequence switch, a circuit is closed from negative pole of battery, the winding of an up-drive magnet 113, second selector sequence switch contacts 11 1 and 115, to positive pole of battery, at the right-hand armature and front contact of relay 102. The up-drive magnet is energized and, in attracting its armature, presses a member 116 into engagement with a roller constantly rotating in the direction indicated by the arrow. Under the control of the up-drive magnet, the brush carriage 117 is moved upward, carrying its brushes 118, 119 and 120 over the terminal sets 121, 122 and 123. A brush 124, by passing over a commutator strip 125, intermittently shunts out the stepping relay 19 over a path from positive pole of battery, brush 121, conducting segment 126, conductor 12?, second selector sequence switch contact 128, to negative pole of battery at relay 102. The operation of relay 49 runs down the counting relays in the well-known manner, and positions the brush set in relation to the desired group.

When the upper zero counting relay is energized, the fundamental circuit is broken and relay 1.02 deenergizes, closing, at its right-hand armature and back contact, a circuit from positive pole of battery, second selector sequence switch contacts 129, 112 to the power magnet 100 of the second selector sequence switch, for moving this switch out of position 2 into position 7. When the sequence switch leaves position 2, the circuit of the up-drive magnet 113 is broken at sequence switch contact 11 1.

The circuits used in the setting up of a successful call to a connector will first be traced. In position 7 of its sequence switch, the second selector tests for an idle trunk in the well-known manner, which it has not been considered necessary to describe. At the conclusion of the testing operation, the second selector sequence switch is moved from position 7 to position 8 over wellknown circuits (not shown). lVhen the brush set comes to rest on the terminals of a trunk leading to an idle connector, a relay 202 at such connector is energized over a circuit from negative pole of battery, relay 202, connector sequence switch contact 203, trunk conductor 20 1, terminal 123, brush 120, second selector sequence switch contacts 130, 115, to the positive pole of battery at the right-hand armature and front contact of relay 102. Relay 102 was energized and locked up over circuits previously traced when the sender sequence switch moved from position 6 to position 8, during which interval the counting relays were restored. When relay 202 pulls up its looks itself to trunk conductor 204, independently of connector sequence switch contact 203, over a path from negative pole of battery, relay 202, conductor 213, connector sequence switch contacts 214, 212, righthand armature and front contact of relay 202, and connector sequence switch contact 215. Relay 202, at its left-hand armature and front contact, closes a circuit from positive pole of battery, connector sequence switch contacts 205, 206, relay 207, to negative pole of battery. Relay 207 is energized and locks itself to conductor 208 at its right-hand armature and front contact, through terminal 121, brush 118, second selector sequence switch contact 131, to positive pole of battery. Relay 207, at its lefthand armature and front contact, closes a circuit from positive pole of battery, connector sequence switch contact 209, and the winding of a power magnet 200 of the connector sequence switch, for moving this switch out of position 1. The connector sequence switch moves into position 2 under the control of its normal contact 201.

In position 2 of the connector sequence switch, a circuit is closed from negative pole of battery, winding of the up-drive magnet 210, connector sequence switch contacts 211,212, armature and front contact of relay 202, to the positive pole of battery, at the right-hand armature and front contact of relay 102 over a path previously described. The energization of the up-drive magnet 210 causes the brush set 229 to be moved over terminal sets in the well-known manner. During the upward movement of the brush carriage, a brush 216 passes over a commutator strip 217 and intermittently shuntsout the stepping relay -19 overa path from positive pole of battery, brush 216, conducting segments of the commutator 217, conductor 218, connector sequence switch contacts 219, 220, trunk conductor 221, terminal 122, brush 119, second selector sequence switch contacts 132, 133, conductors 134:, 105, to relay 102. The operation of stepping relay 49 runs down the counting relays in the well-known manner. When the upper zero counting relay is energized and brush 216 encounters an insulating segment, relay 102 is deenergized, closing, at its right-hand armature and back contact, a circuit from positive pole of battery, second selector sequence switch contacts 129, 112, and power magnet 100, to negative pole of battery, for moving the second selector sequence switch from position 8 to position 16, which is the talking position. The deenergization of relay 102 opens the locking circuit of relay 202, which de'energizes and closes a circuit at its left-hand armature and back contact from positive pole of battery, connector sequence switch contacts 222'and 235, to the power magnet 200 and negative pole of battery, for moving the connector sequence switch out of position 2 into position 16. hen.

the connector sequenceswitch moves out of position 2, the circuit of the up-drive magnet 210 is broken at sender sequence switch contact 211, and the brush set 229 comes to rest on the terminals of a line leading to the desired subscriber.

It has not been considered necessary to disclose the manner in which the line is tested or in which the desired subscriber is signaled. When the sender 3 completed its operation, its sequence switch moved out of position 8, and in doing so completed circuits (not shown) to move the first selector sequence switch from position 11 to position 16. The connection is now completed and the parties may converse.

When the called subscriber answers, a supervisory relay 135 at the second selector is energized and closes at its armature a circuit for a supervisory relay 7 from ground, armature and front contact of relay 135, resistance 136, lower left-hand winding of repeating coil 137, second selector sequence switch contact 138, the lower trunk conductor, first selector sequence switch contact 53, winding of supervisory relay 7, lower right-hand winding of repeating coil 55 to grounded battery.

Upon the completion of the conversation, the called subscriber replaces his receiver upon the hook, thereby deenergizing supervisory relay 135, which, in falling off, deenergizes in turn supervisory relay 7, displaying a'well-known signal to the operator. lVhen the calling subscriber hangs up his receiver, a supervisory relay 8 is deenergized, causing the display of a second signal in the well-known manner. The operator then withdraws the answering plug from the jack and restores the first selector.

During conversation, a relay 139 at the second selector was maintained energized over a circuit from negative pole of battery, relay 139, second, selector sequence switch contact 1410, upper left-hand winding of repeating coil 137, the upper trunk conductor, first selector sequence switch contact 5e and the upper righthand winding of the repeating coil 55, to ground. Relay 102 is also maintained energized during conversation by a circuit through the armature and front contact of relay 139.

lVhen the first selector restores, the circuit of relay 139 is broken at first selector sequence switch contact 5 1. Relay 139 falls off and opens the circuit of relay 102 which falls off in turn and closes, at its righthand armature and back contact, a circuit from positive pole of battery through second selector sequence switch contacts 129 and 112, and the power magnet 100, to negative pole of battery, for moving the second selector sequence switch out of position 16 and into position 18.

In position 18, a circuit is closed from negative pole of battery, winding of downdrive magnet 1&1, second selector sequence switch contact 142, to positive pole of battery. The down-drive magnet is energized and under its control the brush carriage is restored to normal. When the brush carriage arrives in its normal position, a circuit is closed from positive pole of battery, brush 121, a commutator segment 1&3, con ductor 1 11, second selector sequence switch contact 145, and the winding of the power magnet 100, to negative pole or battery, for moving the second selector sequence switch out of position 18 and into position 1.

When the brush set of the second selector moved down from the tern'iinals of the connector trunk, the locking circuit of relay 207 was broken. Relay 207, in falling ofl, closes at its left-hand armature and back contact a circuit from positive pole of battery, connector sequence switch contact and the winding of power magnet 200, to negative pole of battery, for moving the connector sequence switch out of position 16 and into position 18.

In position 18, a circuit is closed from negative pole of battery, winning of downdrive magnet 223, connector sequence switch contact 221, to positive pole of battery. The down-drive magnet is energized and under its control the brush carriage is moved downward. lVhen the connector reaches its normal position, a circuit is closed from positive pole of battery, brush 225, a commutator segn'ient 226, conductor 227, connector sequence switch contact 228, and the winding of the power magnet 200, to negative pole of battery, for moving the connector sequence switch out of position 18 into position 1.

Le us now assume that the brush set of the second selector has come to rest on a terminal set in an unequipped group, such terminal set being indicated by terminals 147, 1-18, 149. The terminal sets in this group and other similar unequipped groups have connection to an operators position in dicated at O over-trunk conductors as indi cated at 300, 301, 302.

At this time the second selector sequence switch is in position 8 and relay 102 is energized. Also the fundamental circuit has again been established through relay 102, as previously described. Stepping relay is intermittently shunted out over a path extending from conductor 105 as follows: couductor 134-, second selector sequence switch contacts 133 and 132, brush 119, terminal 147-, trunk conductor 301, upper arinature and back contact of relay 303,left-hand armature and back contact relay 304, interrupter 305, to the positive pole o1. battery. The interrupter is continuously rotating and actuates stepping relay 49 to successively actuate the counting relays. hen the upper zero counting relay is energized, the fundamental circuit is broken, and relays 49 and 102 are deenergized and the second selector sequence switch moves into position 16, as before described.

In position 16 acircuit is closed for relay 304 as follows: from ground, upper righthand winding of repeating coil 137, second selector sequence switch contacts 146 and 130, brush 120, terminal 148, trunk conductor 300, left-hand windingof relay 304, lower armature and back contact of relay 303, trunk conductor 302, terminal 149, brush 118, second selector sequence switch contact 131, to positive pole of battery. Relay 304 is energized, breaking at its lefthand armature the circuit of interrupter 305. At its right-hand armature, it locks itself to ground over a circuit from negative pole of battery, contact spring 306 of relay 307, right-hand winding of relay 304, to ground at the armature and front contact of relay 304. A circuit is also closed for displaying a signal to the operator, from negative pole of battery, winding of the relay 308, a signal 309, to ground at the right-hand armature and front contact of relay 304.

The operator seeing the signal 309 displayed inserts a plug 310 into a jacket 311,

at which time a circuit is closed from ground, sleeve contacts of plug 310 and jack 311, and the winding of relay 307, to negative pole of battery. Relay 307 is energized and breaks, at its right-hand contact spring, the circuit through the right-hand winding of relay 304, and at its left-hand contact spring closes a circuit from the positive pole of battery, resistance 312, contact spring 313, and the winding of relay 303 to negative pole of battery. Relay 303 is energized and at its upper armature extends trunk conductor 301 to the ring terminal of the jack 311, at the same time'holding open at this point also the circuit of interrupter 305. Relay 303 at its lower armature opens the circuit through the left-hand winding of relay 304 and locks itself to trunk conductor 302.

The operator at 0 may now converse with the calling subscriber and inform him that he has called an unequipped number.

After the operator has given this information, she withdraws the plug 310 from the jack 311, thereby opening the circuit of relay 307, which is deenergized. When the plug is withdrawn from the jack, super- 7 .visory relay 135 is deenergized as before, and

the disconnection and restoration of the switches takes place as before described. When the brush set 117 leaves the terminals 147, 148, 149, the locking circuit of relay 303 is broken and relay 303 falls off. The apparatus at the operators position is now ready to receive another call.

What-is claimed is:

1. In a telephone exchange system, a calling subscribers line, a train of automatic switches by which said line may be connected to any other desired line, each of said switches having terminals for use in obtaining a connection, certain. of the terminals of one of said switches being unequipped as regards substation line connections, an operators position associated with said unequipped terminals, and means at said position for controlling theoperation of the last named switch when connected to unequipped terminals.

2. In a semi-automatic telephone exchange system, a calling subscribers line, a train of automatic switches by which a desired connection may be established, a sending device, an-incoming line and outgoing lines at each of said switches, said outgoing lines. terminating in groups of terminal sets in said switches, an operators position, equipment thereat for informing a calling subscriber if a switch is positioned in a group of unequipped terminals, and an interrupter at said position for operating said sender.

3. In a telephone exchange system, a calling substation line, an automatic switch having terminals for use by said calling line in obtaining connection with called substation lines, certain of said terminals being unequipped as regards substation line connections, a sending device, and an interrupter for operating said sending device when the switch is connected to the unequipped terminals. 7

4. In a telephone exchange system, a calling substation line, an automatic switch having terminals for use by said calling line in obtaining connection with called substation lines, certain of said terminals being unequipped as regards substation line connections, a sending device, operators equipment associated with the unequipped terminals of said switch, and means for operating said sending device when the switch is connected to the unequipped terminals. V

5. In a telephone exchange system, a calling substation line, an automatic switch having terminals for use by said calling line in obtaining connection with called substation lines, certain of said terminals being unequipped as regards substation line connections a sending device, operatofis equipment associated with the unequipped terminals of said switch, and an interrupter operable, when said switch is connected to the unequipped terminals, to actuate said sending device. 7

In witness whereof I hereunto subscribe my name this 15th day of August, A. D.

ALBEN E. LUNDELL. 

